Detection of Trichoderma aggressivum in mushroom compost

The objective of this project is the development of a reliable method to detect the presence (or absence) of Trichoderma aggressivum in mushroom compost that is produced during phase 3 composting.

The Dutch mushroom industry is having problems with the presence of Trichoderma aggressivum in batches of phase 3 compost. The symptoms are depicted in figure 1. These problems have started in springtime 2006. Currently, the presence of Trichoderma aggressivum in phase 3 compost cannot be detected. If phase 3 compost is delivered to the grower, the compost producer has no means of detecting whether the pathogen is present in the compost. At time of delivery to the grower, both infected and healthy mushroom compost look, feel and smell identical. Currently the compost producers neither have a method of preventing infection.

For the compost producers it would be valuable to have a method of early warning, that tells them whether they have an infected compost at their hands. For the mushroom growers it would be valuable to have a lower frequency of infected crops.

Results

In comparison to a non-infected compost, a large number of characteristic volatiles are produced by Trichoderma aggressivum. Currently it is nog clear yet, which of these volatiles can most reliable be used as an indicator for the presence of the pathogen. For this a number of different isolates of the pathogen need to be compared, as well as a number of different batches of compost.